Hard on the heels of the flower people (5)
I believe the answer is:
irish
'people' is the definition.
(the Irish are the people of Ireland)
'hard on the heels of the flower' is the wordplay.
'hard' becomes 'h' (abbreviation used in pencil classifications).
'on' is a charade indicator (letters next to each other).
'the heels of the flower' becomes 'iris' (I am not sure about this - if you are sure you should believe this answer much more).
'h' put after 'iris' is 'IRISH'.
Can you help me to learn more?
(Other definitions for irish that I've seen before include "Native to the Emerald Isle" , "of Hibernia" , "Relating to Ireland" , "Eg, native to Dublin" , "Sort of coffee, stew or terrier" .)